iXchange Issue #7

June 1995

A newsletter for BMW 325 iX Enthusiasts.


iXploits & iXperiences

Here's a followoup from last issue with some additional info from Michael Sand of Corning, NY:

Another modification on my iX-mobile is the installation of a swell stereo to help me along my 3-3.5 hours of commuting each day. My objective was not to simply disembowel myself with sonic oomph but to create a pleasant system which would not make me tire of listening like the stock system did. I have installed an Alpine pullout head unit which controls the Alpine CD changer in the trunk. This is helped along by an Audio Control 12 band per channel EQL, an Alpine EQ used solely for its subwoofer crossover, a three way electronic crossover, and 4 Alpine amps providing 9 channels of amplification totaling 570+ watts rms.

Stock tweeters are in the front door locations (which I will replace with a set of top notch tweets I have floating around the basement when I get the chance). I installed Altec Lansing 4" midranges in the front doors (see installation notes below),and Alpine 5-1/4' component mid-bass drivers in the front kick panel locations. This adds up to quite a nice soundstage from which the artists perform.

For rear fill I am using the stock tweeter/5-1/4" plate speaker which isn't too bad when not asked to produce any bass. In my copious free time I will be swapping those drivers out with some JBL titanium tweeters I happen to have, and some sort of midrange. Finally, a single Rockford Fosgate 10" subwoofer installed nicely where the ski bag fits and did not take up any trunk space. An enclosure of some sort would be better, but I need the space and don't want the additional weight. I installed the woofer in a plate in such a fashion that it can be easily removed and the ski bag clips. On a technical note, I had a problem with oil leaking in the oil idiot light sender area but the volume of oil rapidly increased to a point where it became such a mess that finding the source was difficult. At least the undercarriage got a good dose of Italian rustproofing! It was in fact the oil valve going to the oil cooler. That housing upon which the filter mounts has a large 0 ring against the block. That was questionable, so I replaced that to the tune of about $5. (cheap, yes, but it is still just an 0 ring!) On said housing is a spring loaded valve which diverts oil flow to the cooler. This unit (mine was made by Purolator) has a metal cap which is pressed into its hole with a crummy seal on it. A retaining ring holds it all in place. It was this crummy gasket that made the mess under my car.

The dealer had a rebuild kit for around $12. which included the cap and a much more robust 0 ring seal. I first disconnected the oil cooler lines at the filter and then removed the center bolt going into the block. Be careful removing the retaining clip as it will try to fly straight for your eye (or fender or cat or something) when released. As usual be sure the large 0 ring is properly seated when you reassemble the thing to the block and be sure that there is still adequate clearance for the manila-dirty-oil-flow-diverter-to-keep-your-boots-clean-envelope to slip under the filter for when you change your oil. If the assembly has rotated upon reinstallation, this will be a problem. A good dose of Simple Green and a pressure wash later, and all was back in good order. Might I suggest that replacing those seals become a priority if you like a clean underbody?

I have noticed that the 8xl3 vacuum hoses and that big ribbed rubber intake hose junction thing with the idle control valve mounted to it just before the throttle are showing signs of age. I will replace them after the holidays, I suppose. Better to do so before a leak develops...

Also, you may want to pull the heater blower motor and lubricate the bearings as a preventative measure. Mine has started squeaking on 1 and 2 speeds. I hope that the bearings are not too far gone. According to the manual (I haven't had a chance to do it yet) the motor can be reached by simply removing the cover over the firewall and unclamping and unplugging the blower.


Dave Ritter of Marquette Michigan had to replace the Motronics Electronic Control Unit (ECU) on his '88 iX and has provided some valuable information:

My first indications of a problem came a few months ago when my '88 iX started idling at 1000-1200 rpm when the engine was warm. The idle was fine when cold or warming up, but once normal temperature was reached the high idle speed would kick in and fluctuate slightly plus or minus 50 rpm. I had this checked out and was told I needed a new ECU . My first mistake and most basic problem is that I tried to save money by getting a used part. Vines of Bessemer AL advertised in the Roundel that they were scrapping an '88 iX so I called them to ask about the ECU. They then convinced me that any 325i/is-type ECU would work. I paid them $260 for one out of a 325iC.

When I received it I noticed that the numbers were different. I called them to ask about the difference and they said that their books showed the part number they had sent me to be correct for my car. The number they were checking was the Bosch part number. They told me they would make it right if it didn't work. I then installed it in the car and it started and ran much better with no other apparent problems. The next day when I drove the car, I got an ABS light after driving a few minutes and later noticed the car was idling a little slow once warmed up.

After taking the car into my local mechanic and explaining what I had done to the car, he told me this was the correct ECU and even though the Bosch part number was correct on the used part, the problem was the codes in the unit. The BMW parts sticker on the unit shows their code numbers. For example, the correct part would have code C83E: the one I had in the car showed C5AE. I then contacted Vines to tell them that they had sent me the wrong part. They took about a week to tell me that they could not get me a correct ECU. I told them that I would be returning their part as soon as I could get a new unit. I then contacted my nearest BMW dealer, Enterprise Motors in Appleton, WI. They assured me that they had the correct blank ECU in stock and that they could code and install it in my car for around $450. I set up the appointment and showed up for the miracle cure. The mechanic started shaking his head after connecting his coding unit to my car. I knew this was a bad sign. They spent an hour and a half trying to get all that fancy BMW computer equipment to work to no avail. I left with the old ECU still in the car.

The next week I arrived and got the NEW correct ECU installed and with the correct codes. Driving the car home I noticed the engine was idling much better, and no ABS lights! The next day however the ABS fault reappeared much to my dismay. I reasoned that maybe I did have something wrong with my ABS system. Back again to my local mechanic for ABS trouble shooting. After much intensive diagnostic checking of sensors and relays he could find nothing wrong, even though the ABS continued to fault for him. I began to suspect something was still wrong with my ECU so I contacted Rick Stormer, one of the BMW Technical Advisors listed in the Roundel. Once I described my problem he recognized the problem as a service bulletin not complied with by my dealer. Rick also warned that I might damage my new ECU if I continued driving the car without the modification in place. I then contacted my dealer who initially dismissed my claims. After I assured them that I had been read a bulletin specifically addressing my exact problem, they called back a few hours later to agree with my assessment of the problem. They then denied that driving the car would harm it, but I remained suspicious. They did agree to ship me the needed parts and the service bulletin itself so that I could get it fixed myself for $173 additional dollars thank you. I then called BMW of North America customer service to complain about this dealer and that I would never recommend anyone to visit this dealer again.

I did return the wrong ECU to Vines but have yet to get my money back. I guess I'll see how the credit card companies do on refunds! After long last the car is finally fixed.

Dave provided a copy of the BMW Service Bulletin. I have included it at the end of this issue.

iX Highlights & Features

With their applications for the iX Registry, I get some very interesting info on modifications that members have made to their iX's. Two of the most interesting iX's are described below.

Mark Page of Solon, Ohio, listed the Mods to his Lazur Blue (metallic purple) with Silver Leather iX as follows:

"All European ellipsoid headlights, headlight wiper/washer apparatus with intensive cleaner reservoir, rear fog lights, sport seats, heated wide-angle side mirrors, black exhaust tips, fire extinguisher, adjustable lumbar support, rear storage compartment in trunk, inner trunk lid covering with twin lights, full function trip computer, heated washer jets, illuminated shift knob, '325iXs' rear trunk emblem, etc., etc., etc." Impressive, huh?

Tim Ripley of Morristown, New Jersey, has modified his iX to allow him to enjoy his ultimate driving machine in spite of a situation that would keep less rugged individuals riding the bus. TIm writes:
"I would bet I'm the only iX owner in the U.S. with a microprocessor controller vacuum servo working my clutch for me. I have a system known as "the Clutch" in France where it was designed for persons with disabilities, etc. Although the system has its drawbacks and bugs, it works quite well when it is working well...and it's been keeping me busy when it's not.
"For instance it decided not to work on the morning of my first BMW CCA Drivers School at Lime Rock Park in March. I hadn't even checked the cable because I had assumed rerouting the cable fixed the cause of the problem the first time it broke. Fortunately, Lime Rock is drivable in third gear and you only give up a little on the main straight if you don't want to shift without using the clutch. The cable has now been replaced with an aircraft quality cable which should last. The next project is to come up with a better setup for the shift switch, replace the rubber hose with proper reinforced vacuum line or tubing, and then maybe a proper end fitting for the cable for the throttle position sensor/rotary valve. It's a good thing the car has only required routine maintenance. I like this car so much I want to keep it out of the snow! Also impressive, huh?

Thanks Michael, Dave, Mark and TIm for sharing your iXperiences with us.

BMW Info on the Internet

In the last iXchange issue I mentioned the "bmw-digest" on the internet. Since writing the last issue, I've canceled my America Online account and gotten a more direct internet connection which allows me to run Netscape, Mosaic, Eudora, Fetch, Turbogoper, etc. on my Macintosh with a PPP connection. I've found some great sources of info related to BMW and motorsports in general:

- News about the BMW World Wide Web Server can be found at the Uniform Resource Location (URL): http://cbsgi1.bu.edu/bmw/news.html.

- General BMW information including repairs and service, models and all kinds of great information: http://cbsgi1.bu.edu/bmw/bmw.html.
(The info below about "Check Engine" codes was obtained from this source.)

- Generic info about racing (including F1 and CART schedules and results) can be found at:

If you have a chance to "get wired" and surf the Internet, check out these sites.

Gordon's New e-mail Address

With my new internet account, I have a new address. You can now e-mail to me at:

theiXer@earthlink.net .


The following information was downloaded from the BMW WWW server (http://cbsgi1.bu.edu/bmw/bmw.html). You can do a quick check on the health of your engine by following the procedure described below and reading the flashes of the "Check Engine" light on your instrument cluster. Hopefully it will flash once for about two seconds and then flash the code 1444. Check it out!

Early systems. ('88 iX)

Early systems (Motronic 1.1 only, I think) flash the fault codes automatically. If the check engine light comes on, leave the key in the On position, but don't start the car. The check engine light will begin to flash the code after about 3 seconds. Each flash is separated by about 1 second. There aren't many codes on this system

1 flash......Air flow sensor malfunction.
2 flashes....Oxygen sensor malfunction.
3 flashes....Coolant Temp. malfunction.
4 flashes....Throttle switch malfunction.

More detail on these early systems can be found in the Bentley manuals. (Note: to reset this system, rapidly restart the engine 5 times.)

Late 1980's systems. Motronic 1.1 ('89-'91 iX)

The fault codes for these systems will appear on the check engine light when you turn the ignition key to the On position (but don't start it), then: Fully depress the accelerator pedal, then fully release it. Repeat the depress,release cycle 5 times fairly quickly, but not too fast. It should be completed in a few seconds. What you are doing here is clicking the wide open throttle switch then the idle switch each 5 times. This signals the Motronic unit to send the fault codes by flashing the Check Engine light. You should see the light flash once then it will start flashing the 4 digit codes. If there are no faults, you should see the 1444 code (and 2444 if you have a 12 cylinder). The codes appear as a series of flashes for each digit. The flashes indicating one digit are about 1 second apart, the next digit appears after a couple second interval. The rest of the fault codes appear in Table 1 below.

The most recent systems. Motronic 3.x

The fault codes appear in the same way as for the Motronic 1.x systems listed above, but it is much trickier to get them to appear. The timing with which you turn the key then depress and release the accelerator pedal is much more critical. You have to depress and release the pedal 5 times, rhythmically, but much faster than for the earlier system. It usually takes a few tries to get it right.

This table lists all the fault codes we could find. If anyone has others, please send them to us. The faults listed are for all different models and some of them are not applicable like Fuel Injector 8 on a 6 cylinder car.

Table 1. The Motronic Fault Codes

Malfunctioning System. Fault Code

No Failures               1444
DME Control Unit 1211
Air Mass/Volume Sensor 1215
Throttle Potentiometer 1216
Output Stage, Group 1 1218
Output Stage, Group 2 1219
EGO(O2) Sensor 1 1221
EGO(O2) Sensor 2 1212
Lambda Control 1 1222
Lambda Control 2 1213
Coolant Temp. Sensor 1223
Intake Air Temp. Sensor 1224
Knock Sensor 1 1225
Knock Sensor 2 1226
Knock Sensor 3 1227
Knock Sensor 4 1228
Battery Voltage/DME Main Relay 1231
Throttle Idle Switch 1232
Throttle WOT Switch 1233
Speedometer A Signal 1234
A/C Compressor cut off 1237
A/C Compressor 1242
Crankshaft Pulse Sensor 1243
Camshaft Sensor 1244
Intervention AEGS 1245
Ignition Secondary Monitor 1247
Fuel Injector 1 (or group 1) 1251
Fuel Injector 2 (or group 2) 1252
Fuel Injector 3 1253
Fuel Injector 4 1254
Fuel Injector 5 1255
Fuel Injector 6 1256
Fuel Injector 7 1257
Fuel Injector 8 1258
Fuel Pump Relay Control 1261
Idle Speed Actuator 1262
Purge Valve 1263
EGO Heater 1264
Fault Lamp (check engine) 1265
VANOS 1266
Air Pump Relay Control 1267
Ignition Coil 1 1271
Ignition Coil 2 1272
Ignition Coil 3 1273
Ignition Coil 4 1274
Ignition Coil 5 1275
Ignition Coil 6 1276
Ignition Coil 7 1277
Ignition Coil 8 1278
Control Unit Memory Supply 1281
Fuel Injector Output Stage 1283
Knock Control test Pulse 1286

For 12 cylinder models, there are additional codes for the second Motronic unit. These codes are the same as above, but the first digit (1) is replaced by 2.


(A protective relay, that is.) One morning I opened the garage door and noticed that the parking lights on Bev's iX were dimly lit -- I had left the lights on overnight. Then in my haste to get her off to work, I did a "no-no" and connected the battery charger incorrectly to the battery (reversed connections.) Eventually I got the car started, but the ABS light remained on. Turns out that the brief reversed polarity blew out the relay that is designed to protect the ABS circuitry. This relay is attached to the top of ABS control unit under the dash just to the left of the steering wheel. I ordered a replacement part number 34521154894 for $21.06 from Eurasian Parts Select in Temecula, California (800) 824-8814. This restored the ABS function and turned off the dash light. Next time I'll be more careful. But thank you BMW for protecting the ABS control unit with an effective (but expensive) relay.

BMW SERVICE BULLETIN #34-02-89 (1857)

SUBJECT: ABS Warning Lamp Illumination

MODEL: 1988 325iX (up to and including 5/88 production)

Observation: The ABS system on the 325iX incorporates an additional function to reduce engine braking (at closed throttle) when ABS is activated on low drag coefficient road surfaces.

The ABS Control Unit sends this request via pin 3 to pin 50 of the DME Control Unit.

As part of the ABS self-check, this circuit is continuously monitored. if the control unit determines that the circuit is open or has high resistance the ABS system will be deactivated and the ABS warrning lamp will be illuminated

Situation: Tolerances in DME circuitry (pin 50) can cause this condition to occur. An adapter harness is available to compensate for these tolerances. (BMW Part No. 12 57 1 724 368)

DME 1.3 control units do not have circuitry compatible with the ABS control units originally installed in these vehicles. For this reason an adapter harness must be installed whenever a DME 1.3 control unit is installed into one of these vehicles.

DME 1.1 control units may also exhibit the same problem To determIne if the problem lies in the circuit (or elsewhere In the ABS system) perform the following diagnostic steps.

Note: Call up the DME system via the BMW Service Tester for
positive identification of the control unit (1.1 vs. 1.3).

Diagnostic Procedure
Tools required:
Universal Adaptor w/35 pin adaptor leads
Fluke muitimeter

* Connect universal adaptor between ABS control unit and harness

* Connect multimeter between pin 3 (+) and pin 10 (-).

* Start engine and observe voltage.

* If the voltage is 1.23 or higher an adaptor harness must be installed.

If below 1 .23 V the problem is elsewhere via the ABS system. Use the BMW Service Tester to diagnose the system.

Harness Installation

1) Disconnect engine harness from the vehicle harness at C1O1

2) Remove the connector holder from the firewall and install the additonal mounting bracket.

3) Install both connector holders to this bracket.

4) Connect adaptor harness between the engine and vehicle harness.

5) Secure connector housing in the appropriate connector holders.

6) Attach the ground lead on this adaptor harness to the hood catch

WARRANY INFO: Defect Code 34 53 00 12 00